Liu Haiming

A Heuristic Optimization Algorithm for Multi-head Mounter

This paper analyzes optimization algorithms of assembly time for a multi-head mounter. A step-by-step heuristic optimization algorithm is proposed to minimize the PCB assembly time for a multi-head mounter. By relaxing the restrictions on the problem and employing a flexible approach for feeder and head assignment, the algorithm reduces the assembly time by minimizing cycles of pick and placement, constructing the simultaneous pickup and implementing the nearest placement. The production results show that the proposed algorithm has good performance in practice.

Optimization algorithm based on niche genetic algorithm for irregular nesting problem

This paper presents an improved genetic algorithm based on niche strategy to solve the irregular nesting problem, which exists widely in modern manufacturing industry. For the niche strategy used in genetic algorithm, exclusion mechanism is introduced to avoid too many solutions with high similarity in the population, guaranteeing diversity of the solution set and preventing premature convergence of genetic search. No-fit polygon method based on Bottom-left strategy is used to evaluate the best placement position for every irregular part. Computational experiments based on data set published in the literature are taken to verify feasibility and effectiveness of the algorithm. The experiment results show that the proposed algorithm can be used to solve the nesting problem and generates some better solutions than the solutions published solutions for most examples.

Design and Application of CAD-CAM Data Interface in Electronic Assembly Production

For the wide application of CAD software in current electronic industry, the paper puts forward an idea of designing a kind of data interface between CAD and CAM systems, in order to achieve data sharing and data integration for various equipments in electronic assembly production. Taking component mounting/insertion machines as target equipments, this paper analyzes the data set to be processed by this data interface. Then we describe structure and format of data in a PCB source file generated by Protel, one commonly used CAD software, and discuss how to use the data interface to implement extraction and conversion of production data from a source file. The practical application proves that this data interface can greatly enhance the efficiency of the electronic assembly production.

Optimization Algorithm for Low-Volume and High-Mix PCB Assembly

In this paper, we discuss the process of low-volume and high-mix PCB assembly production in the electronic assembly industry and aim at an effective scheduling method to determine assembly sequence of different types of PCBs to reducing whole production time. The optimization problem can be modeled as an approximate Traveling Salesman Problem (TSP) when considering the effect of machine setup time on whole production time. An optimization algorithm based on Scatter Search method is proposed to search for good solutions to minimize machine setup time. The simulation results show that the proposed algorithm can output good scheduling solutions.

A Fast Subpixel Locating Algorithm with Shielding Case

Aimed at the image locating problem with shielding case, this paper analysis the shortage of general pattern match algorithm then present a fast subpixel locating algorithm based on characteristic edges detect of shielding case. First, it uses binarization and blob analysis method to remove the small particles; Next, it performs a Laplacian transform to get the edge image; And then finds the line segment sets and filter with the size information of the case to get the characteristic edges, And then use Zernike orthogonal moment to get subpixel edges; Finally deduces the center and rotate angle with the characteristic edges. The result shows the locating speed and the accuracy of the algorithm is well and meets the practical application. The algorithm also has strong robust.